Conventionally, there is a known hydraulic cylinder having the structure that moves a piston by supplying a hydraulic fluid (such as oil, water, or fluid) to or discharge a hydraulic fluid from a hydraulic chamber or the structure that pumps or drains a hydraulic fluid by moving a piston. In such a hydraulic cylinder, since an impact (so-called “oil impact”) caused by behavior of a hydraulic fluid may occur, techniques for reducing such an impact are proposed (for example, PTL 1).